Thierry Henry is one of the best strikers of all-time. He’s Arsenal’s all-time leading goal-scorer, and won two Premier League titles with the club. Henry helped France win the 1998 World Cup, and the 2000 Euro Championship. When Henry, 34, signed with the New York Red Bulls of Major League Soccer in 2010, he boosted the sport in the States, giving the league another important does of global credibility. He’s been a star off the field too. In 2007, TIME named Henry to its list of the 100 most influential people in the world. Wrote fellow Frenchman Tony Parker, point guard for the San Antonio Spurs:

He wants to change the world. It’s no secret that European soccer is fighting a racism problem, in the crowd and on the field, and no player has done more to exorcise it than Thierry. After cameras caught Spain’s national coach using a racist slur to describe Thierry in 2004, he could have lost his cool. Instead, Thierry, who is always steady, recruited a host of fellow soccer stars to launch his Stand Up Speak Up campaign, which raised millions of dollars and unprecedented awareness to fight racism.

Henry, indeed, is one of the all-time greats. Even legends, however, can screw up.

If Henry cost the Red Bulls a playoff series Thursday night because he couldn’t chase down a ball he would have knocked in a decade ago, no biggie. Aging legs are aging legs. But no, Henry made the kind of mental mistake you see in pee-wee leagues. As teammate Kenny Cooper took a critical penalty shot in the 69th minute, with the game against D.C. United still scoreless and the two-game aggregate series tied at 1-1, Henry stepped into the penalty box. Since he encroached before Cooper’s foot touched the ball, the penalty shot would not count if it was successful. Of course, Cooper scored, and started celebrating — before the ref told him to do it over. And of course, D.C. United goalkeeper Joe Willis , who just entered the game after starter Billy Hamid got a red card, saved the second attempt. D.C. United’s rookie Nick DeLeon then scored in the 88th minute, sending the D.C. onto the Eastern Conference Finals: they’ll face the Houston Dynamo.

Arrrgh. Imagine, say, Michael Jordan committing a foul-line violation while Scottie Pippen took a game-winning free throw. In a playoff game. That’s essentially what Henry did. I’ll admit, I have something invested here: my son, 6, loves Henry and the Red Bulls. He wears his Henry shirt every other day, it seems. So Henry’s screw-up, and the Red Bull loss, drove him into hysterics. So there’s that.

But honestly, the guy has kind of bugged me recently. As someone with Irish blood, I surely haven’t forgotten his intentional handball during World Cup qualifying in 2009, which led to the goal that knocked Ireland out of the tournament. (“Ireland Cheated out of the World Cup by the Cruel Hand of Thierry Henry,” read a headline in the Guardian. “Thierry Henry is an insincere cheat who has tarnished his reputation for good,” said former Irish international star Tony Cascarino in the Times of London.)

I’ve watched him more closely in recent months, and his body language can be maddening. Sometimes, it doesn’t look like he’s trying. When a teammate muffs a pass or fails to spot Henry open across the field, he stomps his feet, waves his arms, puts his hands on his head, incredulous. Like it’s some kind of federal offense that teammates of Thierry Henry don’t play like Thierry Henry.

More veteran Henry watchers, fill me in: am I overreacting here? Has this just always been his m.o.? In one game I saw, Red Bulls-Toronto F.C., Henry went on to score a goal and assist on three others. So it’s kind of hard to knock the guy.

Except for sneaking into the penalty area, and maybe costing the Red Bulls their season, last night. It’s hard to remember a so-called legend, in any sport, doing something so brainless.